U.S. patent application number 10/785053 was filed with the patent office on 2004-09-30 for file security management method and file security management apparatus.
This patent application is currently assigned to FUJITSU LIMITED. Invention is credited to Kono, Taki, Nimura, Naoki.
Application Number | 20040190715 10/785053 |
Document ID | / |
Family ID | 32985472 |
Filed Date | 2004-09-30 |
United States Patent
Application |
20040190715 |
Kind Code |
A1 |
Nimura, Naoki ; et
al. |
September 30, 2004 |
File security management method and file security management
apparatus
Abstract
A file cannot be opened in a position other than a specified
position in a way such that position information is obtained from a
GPS device and filtered according to an encryption level. Data is
encrypted by using the filtered position information as a key. A
header and a digest are created, and their data are saved. To open
the file encrypted by using the position information, it must be
decrypted by using position information which is specified when the
file is saved, whereby the file cannot be specified in a location
other than the specified location.
Inventors: |
Nimura, Naoki; (Kawasaki,
JP) ; Kono, Taki; (Kawasaki, JP) |
Correspondence
Address: |
STAAS & HALSEY LLP
SUITE 700
1201 NEW YORK AVENUE, N.W.
WASHINGTON
DC
20005
US
|
Assignee: |
FUJITSU LIMITED
Kawasaki
JP
|
Family ID: |
32985472 |
Appl. No.: |
10/785053 |
Filed: |
February 25, 2004 |
Current U.S.
Class: |
380/44 |
Current CPC
Class: |
H04L 9/0872 20130101;
G06F 21/6209 20130101; G06F 2221/2111 20130101 |
Class at
Publication: |
380/044 |
International
Class: |
H04L 009/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 31, 2003 |
JP |
2003-095722 |
Claims
What is claimed is:
1. A file security management method, comprising: encrypting a file
by using, as a key, position information which specifies a position
in which the file can be opened; saving the encrypted file;
decrypting the file by using, as a key, position information which
is detected by a position detecting device; and displaying the
decrypted file.
2. The file security management method according to claim 1,
wherein a selection is made from among a plurality of preregistered
positions when position information in which the file can be
decrypted is selected.
3. The file security management method according to claim 1,
wherein a limitation is imposed on a position range in which the
file can be opened by changing a data length of position
information which is used as an encryption key.
4. A file security management method, comprising: saving data that
is encrypted by using, as a key, position information which
specifies a position in which the data can be used, and the
position information as a key; determining whether or not position
information which is detected by a position detecting device and
the saved key match, and decrypting the encrypted data by using the
key if the position information and the saved key match; and
displaying the decrypted data.
5. A file security management apparatus, comprising: an encrypting
unit encrypting a file by using, as a key, position information
which specifies a position in which the file can be opened; a
saving unit saving the encrypted file; a decrypting unit decrypting
the file by using, as a key, position information which is detected
by a position detecting device; and a displaying unit displaying
the file decrypted by said decrypting unit.
6. A file security management method, comprising: encrypting a file
by using, as a key, position information which specifies a position
in which the file can be opened; and saving the encrypted file.
7. A file security management method, comprising: decrypting an
encrypted file by using, as a key, position information which is
detected by a position detecting device, when opening the file; and
displaying the decrypted file.
8. A file security management method, comprising: encrypting data
by using position information which specifies a position in which
the data can be used; and transmitting the encrypted data, or
saving the encrypted data onto a computer-readable storage
medium.
9. The file security management method according to claim 8,
wherein a limitation is imposed on a position range in which a file
can be opened by changing a data length of position information
used as an encryption key.
10. A computer-readable storage medium on which map information is
recorded, wherein: map data encrypted with position information
which specifies a position in which a user can use the map data is
recorded; and map data, which can be decrypted only if position
information detected by a position detecting device and the
position information used to encrypt the map data match, is
recorded.
11. A program security management method, comprising: encrypting a
program with position information which specifies a position in
which the program can be used; and transmitting the program
encrypted with the position information, or saving the encrypted
program onto a computer-readable storage-medium.
12. The program security management method according to claim 11,
wherein the program is encrypted with the position information, and
a license key given to a user.
13. A computer-readable storage medium on which is recorded a
program that is encrypted with position information which specifies
a position in which the program can be used.
14. A program security management method, comprising: encrypting a
program with position information which specifies a position in
which the program can be used; transmitting the program encrypted
with the position information, and a license key given to a user;
receiving, by the user, the encrypted program and the license key;
and decrypting the encrypted program with position information
which is detected by a position detecting device, and the license
key.
15. A file security management apparatus, comprising: encrypting
unit encrypting a file by using, as a key, position information
which specifies a position in which the file can be opened; and
saving unit saving the encrypted file.
16. A file security management apparatus, comprising: a decrypting
unit decrypting a file by using, as a key, position information
which is detected by a position detecting device; and a displaying
unit displaying the file decrypted by said decrypting unit.
17. A computer-readable storage medium on which is recorded a
security management program for causing a computer to execute a
process, the process comprising: encrypting a file by using, as a
key, position information which specifies a position in which the
file can be opened; saving the encrypted file; decrypting the file
by using, as a key, position information which is detected by a
position detecting device, when opening the file; and displaying
the decrypted file.
18. The computer-readable storage medium according to claim 17, the
process further comprising imposing a limitation on a position
range in which the file can be opened by changing a data length of
position information used as an encryption key.
19. A computer-readable storage medium on which is recorded a
security management program for causing a computer to execute a
process, the process comprising: encrypting a file by using, as a
key, position information which specifies a position in which the
file can be opened; and saving the encrypted file.
20. A computer-readable storage medium on which is recorded a
program for reading map data from a storage medium on which is
recorded map data encrypted with position information which
specifies a position in which the map data can be used, the program
comprising allowing the map data to be decrypted only if position
information detected by a position detecting device and the
position information used to encrypt the map data match.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a file security management
method and a file security management apparatus.
[0003] 2. Description of the Related Art
[0004] With the popularization of networks such as the Internet,
etc., users have been able to access a system via a network.
Generally, to prevent an illegal access to a system, an individual
authentication code is given to a user, and login is permitted if
an input authentication code and a preregistered authentication
code match.
[0005] However, the above described authentication system has a
problem that a person other than a permitted user can make an
access if an authentication code is known to another person.
[0006] To overcome such a problem, there is a technique that
prevents an illegal access by making a cellular phone comprise a
GPS function, by preregistering a position range in which an access
can be made to a system, and by denying an access if the position
of the cellular phone is outside the reregistered position range
(for example, see Patent Document 1).
[0007] There is also a technique that prevents data stored in a
portable information terminal from being leaked by storing the use
behavior range of the portable information terminal onto a storage
medium, and by executing a file deletion process if the current
position of the portable information terminal, which is read from a
GPS control module, is not within the preregistered use behavior
range (for example, see Patent Document 2).
[0008] [Patent Document 1]
[0009] Japanese Patent Publication No. 2002-327562 (FIG. 5, and
paragraphs 0024 and 0025)
[0010] [Patent Document 2]
[0011] Japanese Patent Publication No. 2003-18652 (FIG. 3, and
paragraph 0015)
[0012] In a company, a public institution, a library, etc.,
electronic documents that can be freely viewed in their areas, but
are prohibited from being carried outside exist. Hereafter, as
documents in a company, a public institution, etc. are made
electronic more and more, the number of electronic documents that
are prohibited from being carried outside is expected to
increase.
[0013] An illegal access or an illegal use of data when a cellular
phone or portable information terminal itself is carried outside a
predetermined position range can be prevented. However, an
electronic document can be copied if a position range is within a
permitted position range, or an original electronic document can be
carried outside a permitted position range.
SUMMARY OF THE INVENTION
[0014] An object of the present invention is to make it impossible
to open a file in a location other than a specified location.
[0015] One mode of a file security management method according to
the present invention comprises: encrypting a file by using, as a
key, position information which specifies a position in which the
file can be opened; saving the file which is encrypted by using the
position information as a key; decrypting the file by using, as a
key, position information which is detected by a position detecting
device; and displaying the decrypted file.
[0016] According to the present invention, a file can be freely
opened in a position specified when the file is saved, but cannot
be opened in a position other than the specified position.
Accordingly, even if the file is copied in a location in which the
file can be opened, and carried outside, or even if an information
processing device of a portable type in which the file is stored is
carried to a location other than the specified position, the file
cannot be opened in a location other than the specified location.
As a result, the file can be prevented from being illegally
used.
[0017] Another mode of the present invention is to allow a
selection to be made from among a plurality of preregistered
positions when information of a position in which a file can be
decrypted is selected.
[0018] With such a configuration, an arbitrary position is
specified from among a plurality of preregistered positions when a
file is stored, whereby the position in which the file can be
opened can be specified.
[0019] A further mode of the present invention is to impose a
limitation on a range in which the file can be opened by changing
the data length of position information used as an encryption
key.
[0020] With such a configuration, a position range in which the
file can be opened can be arbitrarily limited, for example, by
truncating which digit and its subsequent digits of position
information, whereby a user can arbitrarily set the strength of
security.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIGS. 1A and 1B show the basic configuration of a file
security management apparatus;
[0022] FIG. 2 explains the functions of an information processing
device according to a preferred embodiment;
[0023] FIG. 3 shows a tool bar of an application;
[0024] FIG. 4 is a flowchart showing a data saving process
according to a first preferred embodiment;
[0025] FIG. 5 shows the relationship between a security level, a
filter, and GPS information;
[0026] FIG. 6 explains a security level;
[0027] FIG. 7 shows the data structure of an encrypted file;
[0028] FIG. 8 shows the structure of a header;
[0029] FIG. 9 is a flowchart showing a process executed when data
is saved by specifying a current location;
[0030] FIG. 10 is a flowchart showing a process executed when data
is saved by specifying latitude and longitude;
[0031] FIG. 11 explains a specification method when data is saved
by specifying a location;
[0032] FIG. 12 is a flowchart (No. 1) showing a process executed
when a file is opened;
[0033] FIG. 13 is a flowchart (No. 2) showing a process executed
when a file is opened;
[0034] FIG. 14 is a flowchart showing a data transmission/saving
process according to a second preferred embodiment;
[0035] FIG. 15 shows the structure of encrypted data;
[0036] FIG. 16 is a flowchart showing a process executed when a
file is opened;
[0037] FIG. 17 explains a third preferred embodiment;
[0038] FIG. 18 is a flowchart showing a process for opening
encrypted map data, according to a fourth preferred embodiment;
[0039] FIG. 19 explains the case where map information is recorded
onto a storage medium;
[0040] FIG. 20 explains the case where an access key is recorded
onto a removable medium;
[0041] FIG. 21 is a flowchart showing a process for executing a
license protection file, according to a fifth preferred embodiment;
and
[0042] FIG. 22 shows the configuration of an information processing
device.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0043] FIGS. 1A and 1B show the basic configuration of a file
security management apparatus according to the present
invention.
[0044] As shown in FIG. 1B, the file security management apparatus
comprises: an encrypting unit 1 encrypting a file by using, as a
key, position information which specifies a position in which the
file can be opened; a saving unit 2 saving the encrypted file by
using the position information as a key; a decrypting unit 4
decrypting the file by using, as a key, position information which
is detected by a position detecting unit 3; and a displaying unit 5
displaying the file decrypted by the decrypting unit 4.
[0045] With this security management apparatus, a file can be
freely opened in a position specified when the file is stored, but
cannot be opened in a position other than the specified position,
whereby the security of the file can be enhanced.
[0046] FIG. 1A shows the basic configuration of another file
security management apparatus. This security management apparatus
comprises: an encrypting unit 1 encrypting a file by using, as a
key, position information which specifies a position in which the
file can be opened; and a saving unit 2 saving the encrypted file
by using the position information as a key.
[0047] With this security management apparatus, a file can be
freely opened in a position specified when the file is stored, but
cannot be opened in a position other than the specified position,
so that the security of the file can be enhanced.
[0048] A file security management method according to a preferred
embodiment of the present invention is described below with
reference to the drawings. The preferred embodiment to be described
below shows an example where a security management program based on
the file security management method is embedded in an application
program for creating a document.
[0049] FIG. 2 explains the functions of an information processing
device (security management apparatus) 11 in which the file
security management program according to the preferred embodiment
is installed. The information processing device is, implemented,
for example, by a personal computer.
[0050] A GPS (Global Positioning System) device (position detecting
device) 12 receives radio waves from a plurality of GPS satellites,
and calculates position information composed of latitude and
longitude data of a current position.
[0051] A filter unit 13 filters the position information to convert
it into position information having a predetermined data length,
and outputs the position information to an encryption module
(encrypting unit) 14. An encryption level of data, namely, to which
extent a position range where a file can be opened is set is
specified by a user. Therefore, the filter unit 13 executes a
filter process, which corresponds to the encryption level specified
by the user, for the position information, and outputs the position
information having a corresponding data length as an encryption
key.
[0052] The encryption module 14 encrypts an input file (document
data) by using, as a key, the position information output from the
filter unit 13.
[0053] A saving unit 15 stores data, which indicates the level of
encryption, in the header of the data of the encrypted file, also
stores a digest created from the encrypted data in a footer, and
outputs these items of data as one file. The encrypted file is
saved in an external storage device such as a hard disk, etc.
[0054] FIG. 3 exemplifies a tool bar in the case where the file
security management program is embedded in an application for
creating a document.
[0055] In a menu in a lower hierarchy of file items of the tool bar
displayed in an upper portion of a display screen, two options such
as "save by specifying the current location", which specifies the
current position as a location in which a file can be opened, and
"save by specifying latitude and longitude", which saves a file by
specifying latitude and longitude of a location in which the file
can be opened, are added in addition to the conventional options
such as "overwrite and save", and "save with a name".
[0056] For example, if "save by specifying latitude and longitude"
is selected, a user can specify latitude and longitude when saving
a file, or can set a pre-specified location in the file as a
location in which the file can be opened. As a method setting a
location in which a file can be opened in a file, data is encrypted
and stored by using, as a key, position information of a location
in which the file can be opened. As a result, when the file is
opened, it must be decrypted by using, as a key, the position
information used for the encryption, thereby making it impossible
to open the file in a location other than the specified
location.
[0057] FIG. 4 is a flowchart showing a process for encrypting and
saving data, according to the first preferred embodiment of the
present invention. The process to be described below is executed by
a CPU of the information processing device 11, and data resultant
form the process is stored in a memory, a hard disk, etc.
[0058] If "encrypt and save" is selected when document data, etc.
is saved, the CPU obtains GPS information from the GPS device 12
(step S11 of FIG. 4).
[0059] Then, if a security level at the time of encryption is
specified by a user, a filter which corresponds to the security
level is specified (step S12 of FIG. 4).
[0060] Next, data to be encrypted and saved is obtained (step S13
of FIG. 4). Then, the data is encrypted by using, as a key, the
latitude and longitude data of the GPS information by a
predetermined number of high-order digits, which is specified by
the filter corresponding to the security level (step S14 of FIG.
4).
[0061] Here, the security level is data for determining data of up
to which digit of degree, minute, and second data of latitude and
longitude data is used as an encryption key.
[0062] In the first preferred embodiment, as shown in FIG. 5, a
filter table 21 which makes a correspondence between a security
level and a filter value is provided. A user specifies a security
level (position range where a file can be opened) when saving a
file, so that data of up to which high-order digit of latitude and
longitude data is determined to be used as an encryption key.
[0063] For example, if a security level 4 is selected,
[111.10.00.00] is selected as a filter value from the filter table
21 shown in. FIG. 5, and this value and longitude data, for
example, 134 degrees 33 minutes 19 seconds 10 ([134.33.19.10]) east
longitude, which is output from the GPS device 12, are multiplied.
As a result of this calculation, longitude data which corresponds
to a digit of 1 of the filter value is output unchanged, and
longitude data which corresponds to a digit of 0 of the filter
value becomes 0, and .left brkt-top.134.30.00.00.right brkt-bot. is
obtained as an encryption key.
[0064] A security level indicates up to which high-order digit of
latitude and longitude data is used as valid data. By changing a
security level, a position range in which encrypted data can be
decrypted can be arbitrarily set.
[0065] A security level 0 in the filter table 21 shown in FIG. 5
corresponds to the case where encryption is not made, and a
security level 1 corresponds to the case where an encryption key
length is the shortest. At this level, a file can be opened in the
widest range. A security level 9 corresponds to the case where all
of digits of longitude or latitude data are used as an encryption
key. At this level, the strength of security can be made
highest.
[0066] FIG. 6 shows a position range determined by a security
level. For example, if an office A exists in a range from 139
degrees 43 minutes 45 to 55 seconds east longitude to 35 degrees 36
minutes 20 to 30 seconds north latitude (range shaded in FIG. 6), a
filter value, which can specify that range, is set. Then, longitude
and latitude data obtained by multiplying the filter value and the
latitude and longitude data of the office A is used as an
encryption key. As a result, the file can be freely opened in any
position within the office A, and cannot be opened in other
locations. Namely, the length of a key used for encryption is
changed, whereby an arbitrary position range determined by latitude
and longitude data can be specified as a location in which a file
can be opened.
[0067] Turning back to FIG. 4. Upon termination of data encryption,
a header and a digest of the encrypted data are generated (step S15
of FIG. 4).
[0068] Next, the header storing data which indicates a security
level, data encrypted by using position information, and a footer
storing the digest are saved as one file (step S16 of FIG. 4).
[0069] FIG. 7 shows the data structure of an encrypted file, which
is created by the above described data saving process.
[0070] As shown in FIG. 7, a header composed of data which
indicates a security level, etc. is added to the beginning of
encrypted data, and a footer composed of a digest of the encrypted
data is added to the end of the encrypted data.
[0071] FIG. 8 shows the structure of the header shown in FIG. 7. In
the header, a file identification header, longitude and latitude
security level data which respectively specify the security levels
of latitude and longitude, longitude and latitude security
sub-level data which respectively specify the security levels of
second or lower data of longitude and latitude data, encryption
method data which specifies an encryption method of data (for
example, encryption using position information, data specifying
encryption using a public key, or the like), data of date and time
when encryption is made, and possessor data 1 and 2 which indicate
data of a possessor who saves data are set.
[0072] The security levels and the security sub-levels of latitude
and longitude in the header are used to create a decryption key
from GPS position information when a file is opened.
[0073] FIG. 9 is a flowchart showing a process executed in the case
of "save by specifying the current location" as a location in which
a file can be opened.
[0074] Firstly, GPS information is obtained from the GPS device 12
(step S21 of FIG. 9). Next, document data is encrypted by using, as
a key, data obtained by performing a hash operation for the GPS
information in the current position (step S22 of FIG. 9). Then, a
header and a footer are added to the encrypted data, which is then
saved in a storage device (step S23 of FIG. 9).
[0075] FIG. 10 is a flowchart showing the process executed in the
case of "save by specifying latitude and longitude" of a location
in which a file can be opened.
[0076] If "save by specifying a location" is selected from the tool
bar, position information of a preset location, or position
information specified by a user at that time is obtained (step S31
of FIG. 10).
[0077] Next, data is encrypted by using, as a key, data that is
obtained by performing a hash operation for the obtained position
information (step S32 of FIG. 10).
[0078] Then, a header and a footer are added to the encrypted data,
which is then saved in the storage device (step S33 of FIG.
10).
[0079] FIG. 11 exemplifies a display of a setting screen on which a
location is specified in the case of "save by specifying latitude
and longitude".
[0080] In the example shown in FIG. 11, a table which makes a
correspondence between each division name of a company and latitude
and longitude data of each location is created beforehand.. When a
user saves a file by specifying an office name, the latitude and
longitude data of the position in which the office exists is read
from the table, and the file is encrypted by using the latitude and
longitude data as a key.
[0081] In this case, the file is encrypted and saved by specifying
the office name, whereby the file can be freely opened within the
corresponding office, and cannot be opened in a location other than
the specified location. As a result, the security of the file can
be enhanced with a simple save operation.
[0082] FIG. 12 is a flowchart showing a process executed when a
file is opened.
[0083] Firstly, whether or not data which indicates a security
level of encryption is stored in a header of a file is examined to
determine whether or not the file is a file encrypted by using
position information (step S41 of FIG. 12).
[0084] If the header stores the data which indicates the security
level of encryption ("YES" in step S41), the process proceeds to
step S42, in which GPS information is obtained from the GPS device
12 added internally or externally.
[0085] Next, the GPS information is filtered based on the security
level read from the header (step S43 of FIG. 12).
[0086] Then, the encrypted data is decrypted by using the filtered
GPS information as a key (step S44 of FIG. 12). The decrypted data
is then read and displayed (step S45 of FIG. 12).
[0087] FIG. 13 is a flowchart showing another process executed when
an encrypted file is opened by using position information.
[0088] Firstly, GPS information (latitude and longitude data) of
the current position is obtained from the GPS device 12 (step S51
of FIG. 13). Next, the file is decrypted by using, as a key, data
obtained by performing a predetermined hash operation for the
latitude and longitude data of the current position (step S52 of
FIG. 13). Then, the decrypted data is read and displayed (step S53
of FIG. 13).
[0089] According to the above described first preferred embodiment,
if an operation for opening a file is performed in a position
(including a range determined by position information) specified as
a position in which the file can be opened, the file can be
decrypted by using the position information of that position, and
its contents can be displayed. If a position in which the file is
opened is different from the specified position, the file cannot be
decrypted by using the position information of that position.
Therefore, meaningful data is not displayed.
[0090] Accordingly, even if a file is copied in a location in which
the file can be opened, and carried outside, the file cannot be
opened in a location other than the specified location. As a
result, the file can be prevented from being illegally used.
[0091] FIG. 14 is a flowchart showing a data transmission/saving
process according to a second preferred embodiment of the present
invention. The second preferred embodiment is an example where data
is encrypted by using position information as a key, and the data
encrypted by using the position information is further encrypted
with a public key of a receiver, and transmitted and saved.
[0092] If the transmission or the saving of a file is specified,
the CPU of the information processing device 11 obtains GPS
position information from the GPS device 12 (step S61 of FIG.
14).
[0093] Next, the position information is filtered based on an
encryption level (security level) (step S62 of FIG. 14).
[0094] Then, the data is encrypted by using the filtered position
information as a key (step S63 of FIG. 14).
[0095] Next, a digest of the encrypted data is created (step S64 of
FIG. 14). Here, the digest indicates data resultant from a
predetermined hash operation performed for the encrypted data.
[0096] Next, the data encrypted by using the position information,
a header composed of information which indicates an encryption
level, etc., and a footer composed of the digest are encrypted with
the public key of the receiver of the message (step S65 of FIG.
14).
[0097] Then, a predetermined hash operation is performed for the
text encrypted with the public key of the receiver (data which is
encrypted with the public key and composed of the GPS encryption
header portion and the GPS encryption footer portion) to create a
digest (step S66 of FIG. 14).
[0098] Next, a public key encryption header portion is added to the
text encrypted with the public key of the receiver, and the created
digest is stored in a public key footer portion, and the data is
then transmitted or saved (step S67 of FIG. 14).
[0099] FIG. 15 shows the structure of data created with the above
described data transmission/saving process.
[0100] As shown in FIG. 15, data to be transmitted is composed of a
public key encryption header portion, a text encrypted with a
public key, and a public key encryption footer portion storing a
digest. The text encrypted with the public key is composed of a GPS
encryption header portion storing data which indicates an
encryption level, etc., data encrypted by using GPS position
information as a key, and a GPS encryption footer storing a
digest.
[0101] FIG. 16 is a flowchart showing a process executed when a
file encrypted by using position information and a public key is
received and opened.
[0102] A predetermined hash operation is performed for a text
encrypted with a public key to create a digest, and whether or not
the created digest and a digest stored in a footer portion match is
checked (step S71 of FIG. 16).
[0103] If the digests match, the encrypted text is decrypted with a
secret key of a receiver (step S72 of FIG. 16). As a result of
decrypting the encrypted text with the secret key of the receiver,
a GPS encryption header portion, a text encrypted with GPS
information, and a GPS encryption footer portion are obtained.
Then, data which indicates an encryption level is obtained from the
GPS encryption header portion (step S73 of FIG. 16).
[0104] Next, a predetermined hash operation is performed for the
text encrypted by using the position information to create a
digest, and whether or not the created digest and the digest stored
in the GPS encryption footer portion match is checked (step S74 of
FIG. 16).
[0105] If the digests match, position information is obtained from
the GPS device 12 (step S75 of FIG. 16). The position information
is then filtered based on the encryption level obtained from the
GPS header portion, and converted into position information having
a data length which corresponds to the encryption level (step S76
of FIG. 16).
[0106] Next, the encrypted text is decrypted by using the filtered
position information as a key (step S77 of FIG. 16).
[0107] Then, the decrypted data is extracted and displayed on the
display device (step S78 of FIG. 16). The process of step S78 may
be executed as a process separate from the process for decrypted
encrypted data, or part of its process.
[0108] According to the above described second preferred
embodiment, a file is encrypted by using, as a key, position
information which specifies a position in which the file is opened,
and the encrypted data is further encrypted with a public key
encryption method and transmitted, whereby a receiver who has a
secret key can open the file only when he or she stays in a
particular position. As a result, the security of the file can be
further enhanced. In the second preferred embodiment, the method
encrypting a file by using position information as a key, and an
encryption system using a known encryption system can be used
together.
[0109] FIG. 17 explains a third preferred embodiment according to
the present invention, in which encryption using position
information is applied to map information.
[0110] According to the third preferred embodiment, map information
encrypted by using position information is recorded onto a storage
medium such as a CDROM, a DVD, etc. and provided to a user, and the
user decrypts the map information by using the position information
as a key.
[0111] A provider of map information encrypts map information by
using, as a key, position information which specifies an area,
records the encrypted map information onto a storage medium 31, and
sells the storage medium 31.
[0112] A user who purchases the storage medium 31 on which the map
information is recorded sets the storage medium 31 in a reading
device of a car navigation system. When a car driven by the user
runs within a valid range where the map can be used, the map
information recorded onto the storage medium 31 is decrypted by
using, as a key, the position information obtained by a GPS device
mounted in the car navigation system, whereby the map information
can be displayed on a display device 32 of the car navigation
system.
[0113] In the meantime, when the car driven by the user runs
outside the valid range, the encrypted map information cannot be
decrypted even if the user attempts to decrypt the map information
by using the position information obtained by the GPS device.
Therefore, the map information cannot be displayed on the display
device 32.
[0114] According to the above described third preferred embodiment,
a provider side of map information encrypts map information by
using position information as a key, so that a limitation can be
imposed on the use of a user to allow the user to use only map
information within a permitted range. In the meantime, the user
side can display necessary map information without performing a
particular input operation for decrypting the map information.
[0115] FIG. 18 is a flowchart showing a process for opening
encrypted map data, according to a fourth preferred embodiment of
the present invention.
[0116] According to this fourth preferred embodiment, a company
which sells a car navigation system, or the like encrypts map data
with an access key and position information and transmits the
encrypted map data to a user, and the user decrypts the map data
with the position information and the access key.
[0117] The map data in the fourth preferred embodiment is encrypted
with position information that specifies an area where the map data
can be decrypted, and the encrypted map data is further encrypted
with the access key that indicates a user right of the user.
[0118] Firstly, a predetermined hash operation is performed for
encrypted map data that is received wirelessly or via a
communications line to create a digest, and whether or not the
created digest and a digest added to the map data match is checked
(step S81 of FIG. 18).
[0119] If the digests match, the map data is decrypted with the
access key given to the user (step S82 of FIG. 18).
[0120] Next, data that indicates an encryption level is obtained
from a GPS encryption header portion of the decrypted data (step
S83 of FIG. 18).
[0121] Then, a predetermined hash operation is performed for the
data decrypted with the access key to create a digest, and the
created digest is checked by being compared with a digest added to
a GPS encryption footer (step S84 of FIG. 18).
[0122] If the digests match, position information of the current
position is obtained from the GPS device (step S85 of FIG. 18).
Furthermore, the position information is filtered based on the
encryption level obtained from the header (step S86 of FIG. 18). In
the process of step S86, the position information is filtered by
truncating data of the position information by a certain number of
low-order digits according to the encryption level, and a
limitation is imposed on a position range in which the encrypted
data can be decrypted.
[0123] Next, the map data is decrypted by using the filtered
position information as a key (step S87 of FIG. 18).
[0124] Then, the decrypted map data is read and displayed on a
display device of a car navigation system (step S88 of FIG. 18).
The process of this step S88 may be included in the process for
decrypting encrypted map data, or may be executed as a process
separate from the decryption process.
[0125] FIG. 19 explains the case where map information of a
plurality of areas are encrypted and recorded on a single storage
medium (CDROM, DVD, etc.).
[0126] The example shown in FIG. 19 is intended to encrypt map
information of a plurality of areas by using, as keys, an access
key and position information which specify the areas, to record the
encrypted map information onto a storage medium 31, and to give an
access key, in which a use right of areas that the user can use is
set, to the user who purchases the map information.
[0127] The user who purchases the storage medium 31 on which the
map information is recorded sets the storage medium 31 in a reading
device of a car navigation system, and inputs the access key given
from a seller of the map information. The car navigation system
decrypts the map information recorded on the storage medium 31 by
using as keys the access key and the current position information
obtained by a GPS device.
[0128] For example, if the user purchases map information of South
Kanto, the map information is decrypted by using as keys an access
key in which a use right of the map information of South Kanto is
set and the position information obtained by the GPS device, so
that the map information of South Kanto can be displayed on the
display device 32. In this case, since map information of other
areas cannot be used with that access key, it cannot be
decrypted.
[0129] Additionally, if the user purchases map information of
eastern Japan, the map information is decrypted by using as keys an
access key in which a use right of the map information of eastern
Japan is set, and the position information obtained by the GPS
device, whereby the map information of all of areas of eastern
Japan can be displayed on the display device of the car navigation
system.
[0130] In the example shown in FIG. 19, map information of all of
areas in Japan are encrypted by using as keys an access key and
position information of each of the areas, and recorded on a single
storage medium 31, whereby a range of map information that a user
can use can be arbitrarily set. Additionally, storage media 31,
which are provided to a plurality of users whose use ranges of the
map information are different, can be made common. As a result, the
number of man-hours required to create the storage media 31 can be
reduced. Furthermore, a user can use map information of a plurality
of areas with a single storage medium by acquiring an access key
with which the plurality of areas can be used, even if the user
requires the map information of the plurality of areas.
[0131] FIG. 20 explains the case where an access key is saved on a
removable medium.
[0132] Procedures for decrypting map information in the example
shown in FIG. 20 are fundamentally the same as those of the example
shown in FIG. 19. A difference exists in a point that an access key
is saved on a removable medium 33, and a user can decrypt map
information of an area whose use right is possessed by the user by
inserting the removable medium 33 into a removable medium reading
device of a car navigation system when the user uses the map
information.
[0133] In the example shown in FIG. 20, a user can display
necessary map information only by inserting the removable medium
into the reading device, so that the user does not need to remember
the access key in addition to the effects of the encryption method
shown in FIG. 19. Furthermore, a map information provider side can
prevent the access key from being copied to illegally use map
information. This is because the map information cannot be
decrypted if the removable medium is not used.
[0134] FIG. 21 is a flowchart showing a process for executing a
license protection file, according to a fifth preferred embodiment
of the present invention.
[0135] This fifth preferred embodiment shows an example where
encryption using position information is applied to software
execution. A provider that provides software via a communications
line makes a user input a location in which a computer is installed
when the user purchases a license for downloading the software, and
issues position information that identifies the location as license
information. The license information may be issued offline at this
time.
[0136] When the user obtains the license information for
loading/executing or downloading the software, he or she accesses a
server to start the procedures for downloading the software.
[0137] Firstly, position information is obtained from a GPS device
connected to the computer (step S91 of FIG. 21).
[0138] Next, a comparison is made between the position information
obtained from the GPS device and the license information, and
whether or not the position information and the license information
match (step S92 of FIG. 21).
[0139] If the position information and the license information
match, the process proceeds to step S93, in which the software
program is downloaded from the server and decrypted with the
license information to regenerate the original program. When the
program is transmitted from the server, it is transmitted by being
encrypted with the position information which is registered by the
user. The same method can be used also in the case where the
program is downloaded not from a network but from a disk into a
memory. Accordingly, this method can be applied to a stand-alone
system.
[0140] If the position information obtained from the GPS device and
the license information mismatch, the process is terminated without
downloading the software (step S94 of FIG. 21).
[0141] According to the above described fifth preferred embodiment,
loading/execution or downloading of software (a software program?)
can be made only in a location which is registered when an access
key is obtained and in which a computer is installed, and cannot be
made even if an access key is illegally obtained. Accordingly, the
program can be prevented from being illegally obtained, and
protection of the software can be further strengthened.
Additionally, the program cannot be decrypted in a position other
than a specified position by encrypting the program with position
information, whereby the program cannot be used in other locations
even if it is copied.
[0142] Note that a license key, which is given to a user who
purchases the software, may be encrypted with position information
of a location in which a computer of the user is installed, and may
be issued.
[0143] In this way, a license key cannot be properly decrypted in a
location other than a registered location when a program is
downloaded or installed with the license key, whereby the same
license key cannot be used in a plurality of locations. In this
case, the program itself does not need to be encrypted with
position information.
[0144] An example of hardware configuration of an information
processing device 11 according to a preferred embodiment is
described next with reference to FIG. 22.
[0145] A CPU 41 executes a process for encrypting and saving data
with position information, a process for decrypting the data
encrypted with the position information, and the like. A GPS device
42 receives radio waves from a plurality of satellites, and
calculates position information of a current position.
[0146] In an external storage device 43, a program executed by the
CPU 41 is stored, and also data of a process result, etc. are
stored. A memory 44 is used as various types of registers used for
arithmetic operations.
[0147] A storage medium driving device 45 reads/writes from/to a
portable storage medium 46 such as a CDROM, a DVD, a flexible disk,
an IC card, etc.
[0148] An input device 47 is a device inputting data, such as a
keyboard, etc. An output device 48 is a display device, etc.
[0149] A network connecting device 49 is a device for making a
connection to a network such as a LAN, the Internet, etc. A program
can be downloaded from a server of an information provider on the
network via this device. Note that the CPU 41, the memory 44, the
external storage device 43, etc. are interconnected by a bus
50.
[0150] The above described preferred embodiments refer to the cases
where the security management program according to the present
invention is embedded as a plug-in of a document creation
application. However, the present invention is not limited to these
implementations, and can be implemented as a dedicated program for
encrypting a file or data by using position information as a key
and for storing the encrypted file or data, or for transmitting the
encrypted file or data.
[0151] According to the present invention, a file can be freely
opened in a location specified when the file is stored, but cannot
be decrypted and opened in other locations, whereby the security of
the file can be enhanced. Additionally, data is encrypted with
position information and recorded onto a storage medium, so that a
limitation is imposed on a location in which a user can use the
data. Furthermore, a program is encrypted with position
information, whereby a limitation is imposed on a location in which
a user can use the program.
* * * * *